Abstract In any redundant system, the state of the standby unit is usually taken to be hot, warm or cold. In this paper, we present a new model of a two unit standby system wherein the standby unit is put in cold state for a certain amount of time before it is allowed to become warm. Upon failure of the online unit, the standby unit, if in warm state, instantaneously starts operating online; if it is in cold state, an emergency switching is made which takes it to warm state (and hence online) either instantaneously or non-instantaneously—each with some probability; if it is under repair, the system breaks down. Assuming all the associated distributions to be general except that of the life time of the standby unit in the warm state, various reliability characteristics that are of interest to reliability engineers and system designers are derived. A comprehensive cost function is also constructed and is then optimized with respect to three different control parameters numerically. In addition numerical results are presented to illustrate the behaviour of the various reliability charcateristics derived.
[1]
N. Ravichandran.
Stochastic Methods in Reliability Theory
,
1991
.
[2]
M. N. Gopalan,et al.
Stochastic analysis of a one-server two-unit (dissimilar) system subject to slow switch
,
1985
.
[3]
Prabhaker Reddy,et al.
Standby redundancy in reliability - a review
,
1986,
IEEE Transactions on Reliability.
[4]
Toshio Nakagawa,et al.
Bibliography for Reliability and Availability of Stochastic Systems
,
1976
.
[5]
R. Subramanian,et al.
A redundant system with non-instantaneous switchover and “preparation time” for the repair facility
,
1981
.
[6]
Frederick S. Hillier,et al.
Introduction of Operations Research
,
1967
.
[7]
L. R. Goel,et al.
Profit function analysis of system with mixture of warm and cold standby
,
1990
.
[8]
H. Kunzi,et al.
Lectu re Notes in Economics and Mathematical Systems
,
1975
.